In-situ method of fracturing gas shale and geothermal areas

Abstract

A method is provided for in-situ production of oil shale, gas via gas (methane) hydrates and gas shale, and steam via geothermal formations wherein a network of fractures is formed by injecting liquified gases into at least one substantially horizontally disposed fracturing borehole. Thereafter, heat can be applied to liquefy the kerogen or to dissociate the gas (methane) hydrates so that oil shale oil and / or gases can be recovered from the fractured formations.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. Ser. No. 11 / 074,150, filed Mar. 7, 2005; which claims benefit of U.S. Provisional Application 60 / 571,183, filed May 14, 2004, both of which are incorporated herein by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not applicable. BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention relates to in-situ methods of producing oil shale, gas shale, geothermal areas, and gas (methane) hydrates, and more particularly but not by way of limitation, to methods of forming fractures in formations by injecting liquified gases into at least one substantially horizontally disposed fracturing borehole drilled into the formation. [0005] 2. Brief Description of Related Art [0006] Oil shale formations underlie large sections of Western Colorado, Eastern Utah and Southern Wyoming. These formations can be several thousand ...

AI Technical Summary

Benefits of technology

[0017] In accordance with the present invention, a method for forming fractures in a formation to enhance recovery of oil shale oil from shale oil, gas from gas hydrates and gas shale, and steam from geothermal wells is provided. In one aspect, the method of forming fractures in a formation includes providing a substantially vertically disposed borehole (i.e. a motherbore) and a plurality of substantially horizontally disposed boreholes extending outwardly from the substantially vertically disposed borehole. Each of the substantially horizontally disposed boreholes is provided with a remotely controlled valve assembly so that the substantially horizontally disposed boreholes can be selectively closed off from the wellbore or selectively opened to provide fluid communication between one or more of the substantially horizontally disposed boreholes and the substantially extending vertically extending borehole. Of the plurality of substantially horizontally disposed boreholes, at least one is an injection borehole, at least one is a fracturing borehole, and at least one is a production borehole.

Problems solved by technology

The efforts proved too costly and environmentally unfriendly.

When drilling into gas hydrate zones in subterranean formations problems are often encountered because the heat of drilling fluids warms the hydrates near the wellbore, dissociating them and creating craters and sink holes against the casing wellbore.

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